FreeBSD Device Drivers: a guide for the intrepid (book)

“Device drivers make it possible for your software to communicate with your hardware, and because every operating system has specific requirements, driver writing is nontrivial.

When developing for FreeBSD, you’ve probably had to scour the Internet and dig through the kernel sources to figure out how to write the drivers you need. Thankfully, that stops now.

In FreeBSD Device Drivers, Joseph Kong will teach you how to master everything from the basics of building and running loadable kernel modules to more complicated topics like thread synchronization. After a crash course in the different FreeBSD driver frameworks, extensive tutorial sections dissect real-world drivers like the parallel port printer driver.”